Improvement in rock-drillimg machines



EDIVARD S. VINCHESTER, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN ROCK=DRILLING MACHlNES.

Specification forming part of Letters Patent No. 148,2?3, dated March 3,1874; application filed January 15, 1874.

To all whom it may concern:

Be it known that I, EDWARD S. WiNonEs- TER, of Boston, in the county ofSuffolk and State of ll'lassa'chusetts, have invented certainImprovements in Rock-Drilling Machines, of which the following is afull, clear, and exact description, reference being had to theaccompanying drawings making part of this specification, in which-Figure 1 is a longitudinal central section, representing a rock-drillhaving my improvements applied thereto.

My invention consists in partially rotating the piston-rod at eachbackward stroke by means of a jet of air or steam directed from theinduction-port upon the head of the piston, which is fluted, orotherwise provided with ledges or projecting surfaces for it to impingeagainst, by which arrangement the end of the drill is made to strike anew portion of the rock at each blow, thereby facilitating the formationof the hole or bore required.

To enable others skilled in the art to understand and use my invention,I will proceed to describe the manner in which I have carried it out.

In the said drawings, A is the cylinder, 13 he piston, and O thepiston-rod, ot' a rockdrill. a a are the induction, and Z) Z) theexhaust, ports, controlled, respectively, by the inlet-valves c c andthe outlet-valves d [1. cf

are the valve-stems, connected with eccentric rods 1 h, operated byeccentrics i k on the crank-shaft D of a small independent motor orengine, driw'en by air, steam, or other suitable power, and secured bybolts or otherwise to the back or rear head of the cylinder A of therock-drill. E is the cylinder, and F the piston, of my said independentengine, the piston-rod l of which is secured to the crank-shaft D. m aare the ports or passages by which air or steam is admitted into thecylinder E. These ports are controlled by a single valve, G, secured tothe valve-stem 0, connected with an eccentric rod, 1), operated by theeccentric g on the crank-shaft D. The head'of the piston is fluted at 5,and the inner end of the inductionport a is curved around toward it, soas to direct a jet of steam or air thereon at each bacla ward stroke ofthe piston, in order that the piston-rod may be partially rotated, toinsure the end of the drill striking the rock at a different point ateach succeeding blow, whereby the hole is formed with greater ease andrapidity.

From the foregoing construction it will be seen that, as steam or air isadmitted into the cylinder E of the in dependent motor, the crankshaft Dis revolved, causing (through the connections above described) theiiuluction-valve c of the cylinder of the rock-drill to open, thusallowing steam or air to enter and move the piston B in the direction ofthe arrow, the exhaust-port I) being open. On the completion of thetorward stroke of the piston, the induction-valve c is closed and that 0opened, the exhaust I) being open and thatb being closed,

thereby causing the piston to move in the opposite direction, the actionof the valves being positive, and the valves moving with unerringcertainty, irrespective of the length of the stroke of the piston andthe amount of feed of the drill.

By the employment of an independent motor for actuating the valves ofthe cylinder of the drill, the latter is made to follow the movement ofthe valves, and is entirely dependent thereon, instead of controllingtheir action, as in rock-drills ot' the ordinary construction;consequently the wear and breakage of the parts, and the suspension ofthe work incident thereto, are avoided.

I claim A piston the head of which is fluted or provided with ledges orprojections, in combination with an induction-port so formed as todirect a jet of steam or air across them, substantially as described,for the purpose setforth.

itness my hand this 12th day of January, 1874.

EDIVARD S. WINCHESTER.

In presence of- N W. STEARNS, W. J. CAMBRIDGE.

